There are a few terms in pathology that should automatically make you think of specific diseases. In hematopathology, “cerebriform lymphocyte” should make you think of Sezary syndrome/mycosis fungoides; “hypersegmented neutrophil” should bring to mind megaloblastic anemia, and the crude but descriptive “butt cell” should summon up follicular lymphoma (when follicular lymphoma cells circulate in the blood, they often have a derriere-like appearance due to large clefts that extend deeply into the cell).
Another such term is “starry-sky pattern.” In Burkitt lymphoma (which is, by the way, the same thing as B-cell acute lymphoblastic leukemia), the histologic sections have a unique appearance at low power, as seen in the above image. The tumor cells, which are large with minimal cytoplasm, are closely apposed to each other, forming a dark blue background (the “sky”). These cells have a very high turnover rate, so the macrophages that happen to be hanging around get stuffed with cellular debris (they are at this point called “tingible body macrophages”), and upon fixation, the cytoplasm falls away, leaving round white spaces filled with debris (the “stars”). This pattern can be seen on both bone marrow or lymph node sections, and it is quite specific for Burkitt lymphoma.
By the way, tingible body macrophages in and of themselves are not malignant, and they are seen in conditions other than Burkitt lymphoma. In normal germinal centers, for example, they are abundant. This is a point where students often say, well how am supposed to tell, then, whether it is Burkitt lymphoma or a benign reactive lymphadenopathy with germinal centers? The answer is: you have to look at the cells surrounding the tingible body macrophages. If there are sheets of medium-sized dark blue cells, with a high mitotic rate and no architectural pattern whatsoever, it’s probably Burkitt lymphoma. If there are follicles with a mantle zone (dark blue) surrounding a central germinal center (which, by the way, is composed of a ton of different kinds of cells – little ones, big ones, cleaved ones, non-cleaved ones), it’s probably a benign reactive process.
Thanks Dr.Krafts!
You make patho so much more interesting by filling in the gaps in-between the high-yield stuff, while keeping it short and sweet.
Hi, great idea for a site, lots of work obviously gone in and a great resource. Quick point on this post though; Burkitt’s is not the same as ALL at all, they are very different diseases and have totally different presentations, prognoses, causes and treatments.
Actually, in the 2008 WHO classification, the type of B-lineage ALL previously classified as “B-cell ALL” was designated as the equivalent of Burkitt lymphoma. The correct way to refer to these neoplasms is by using one name: “B-cell acute lymphoblastic leukemia/Burkitt lymphoma” or simply “Burkitt leukemia/lymphoma.” Here is a 2012 reference.
We have in the last month two case of burkitt lymphoma very closely resemble to above picture .
Thanks from your web site because your publication is very useful particularly for pathology students.
I am 2nd year pathology resident.
Thanks
Thanks, Dr. Mirwais! I’m glad you find Pathology Student useful! Best wishes in your residency, and beyond.
Great review! But i am somewhat confused about one thing: if acute leukemia is characterized by immature cells, how can Burkitt’s leukemia be considered a type of ALL, when B mature cells are present?
Great question!! The cells in Burkitt look much more like blasts (fine chromatin + nucleoli) than mature B cells (which have clumped chromatin) – so it has traditionally been considered a type of ALL (it used to be called ALL-L3, then B-cell ALL, then just Burkitt leukemia). Although they look like blasts, the cells in Burkitt leukemia do NOT express TdT (terminal deoxynucleotidal transferase, an enzyme made by blasts). So in that sense, they are mature (mature B cells lack TdT).
But can the cells in Burkkit be considered fully mature if they still have fine chromatin and nucleoli? Those aspects are usually associated with immature cells..
No – I personally would not consider them fully mature! It kind of depends on how you define “mature.” If you’re just going on appearance, then no, they are not mature. They look like blasts! If you’re going on TdT expression alone, then they are mature (mature cells don’t express TdT). If you’re going on clinical course, then no, they are not mature (they act much more like blasts: fast growing, aggressive). Taking everything together, they are classified in our current system as “mature” but that is just a name – I think they are still thought of as blasts. Weird, TdT-negative blasts, but blasts.
Thanks Dr. Kraft!
Your insight is very much appreciated and made everything clear. From now on, I’ll be sure to check your wonderful website whenever I have any doubt on path.
Starry sky finally has meaning to me. Thank you
Thanks Dr. Kraft!
but i have a question, why the cytoplasm of tingible body macrophages falls away upon fixation??
So what are the malignant cells in burkitt lymphoma
If you mean where are they in the starry-sky pattern: they are the sky!
Oh goodness – I don’t know!
I did not know that they did not express TdT. Always learn something new. 🙂 Thanks